An analysis of cropland carbon sequestration estimates for North Central Monana

A pilot cropland carbon sequestration program within north central Montana has allowed farmers to receive carbon credit for management adjustments associated with changing from tillage-based agricultural systems to no-till. Carbon credit can also be obtained by adopting conservation reserve, where cropland is planted into perennial vegetation. Summer fallowing is also considered within the crediting process as credit is not given in years that a field is left un-vegetated. The carbon sequestration program has been advocated as a means to mitigate climate change while providing an added source of income for Montana farmers. There is lack of data, however, pertaining to the percentage of lands within this region that have not converted to no-till management, lands under certain crop intensities (e.g. those that are cropped every growing season vs. those that use a fallow-cropfallow system), or cropland that have converted to perennial vegetation outside of the popular Conservation Reserve Program. Data is also sparse concerning the amount of soil organic carbon that might be sequestered given a conversion to notill or conservation reserve. This study established regional percentage estimates of cropland under no-till, various degrees of crop intensity, and conservation reserve within north central Montana. Literature-based carbon sequestration estimates were used to generate carbon gain data associated with the conversation to no-till and to conservation reserve. These estimates were then applied to the area-based cropland statistics to estimate potential regional carbon sequestration associated with these management changes. J. D. Watts (B) Department of Forestry, University of Montana, NTSG, Rm. 424, 32 Campus Drive, Missoula, MT 59803, USA e-mail: [email protected] R. L. Lawrence · P. Miller · C. Montagne Department of Land Resources and Environmental Science, Montana State University, Bozeman, MT 59717, USA R. L. Lawrence e-mail: [email protected] 302 Climatic Change (2011) 108:301–331